Days away from the release of Teenage Time Killers’ debut, Greatest Hits Vol. 1 -- which is already streaming in full ahead of its July 31 arrival -- the massive collective’s ringleader, Reed Mullin of Corrosion of Conformity, and other key players like Foo Fighters’ Dave Grohl, have opened up about how the unique project came about in the first place.

Teenage Time Killers serve as a pretty good definition for “supergroup.” In addition to Mullin and Grohl, the album also features Lamb of God’s Randy Blythe, former Dead Kennedys frontman Jello Biafra, Slipknot’s Corey Taylor, Alkaline Trio and Blink-182’s Matt Skiba, Queens of the Stone Age’s Nick Oliveri and 22 more guests. With that many heavy hitters in tow, it makes sense that the project is really the work of a friendship 30 years in the making.

Mullin and Grohl met during Corrosion of Conformity’s gigs in D.C. in the ‘80s, and Mullin became a sort of mentor to the soon-to-be Nirvana drummer.

“This kid would approach me every time we’d play D.C.,” Mullin told Rolling Stone. “It ended up being Dave Grohl, and he followed me around and learned how I did triplets and stuff like that. It took him, like, two weeks to figure out all the s--- I knew how to do.”

“Reed was my drumming hero when I was 15 or 16,” Grohl added.

Fast forward three decades, and Grohl invited Corrosion of Conformity to record their 2012 eponymous album at his Studio 606. Eventually, Mullin began recording an EP with Teenage Time Killers’ other two original members, sound engineer John “Lou” Lousteau and My Ruin and Birds of Satan’s Mick Murphy. From there, the collaborations continued to snowball, bringing Biafra, Blythe and others into the fray.

Now, Mullin is looking ahead to the future. Mullin told Rolling Stone he already has handful of songs written for a follow-up and is considering what guests should appear on the second album. Likewise, he’s also in the midst of orchestrating a few Teenage Time Killers concerts in L.A., New York, Chicago, Seattle and London. “Even if we get two-thirds of the people, it’ll be a big show,” Mullin noted.